Generally — Most Areas
false sunflower (zones 4-9) partially overlaps with New Hampshire (3b-6a). It can grow in zones 4-6 within the state.
Your yard isn't the whole zone.
New Hampshire spans zones 3b-6a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score false sunflower against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Zone Comparison
False Sunflower Needs
- USDA Zones: 4-9
- Soil pH: 5 - 7.5
- Sun: Full Sun
- Drainage: well (dry spells)
- Frost-Free Days: 90+
New Hampshire Has
- USDA Zones: 3b-6a
- Last Frost: May 1 - Jun 1
- First Frost: Sep 10 - Oct 10
- Annual Rainfall: 36-50 inches
- Common Soils: Glacial till, Sandy loam, Rocky loam
Plant Zone Range (zones 4-9)
Preferred Soil pH
Plant data: USDA PLANTS Database / plant_species_v5.csv. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant False Sunflower in New Hampshire
The frost window
Across New Hampshire, the last spring frost clears between May 1 and Jun 1, and the first fall frost lands between Sep 10 and Oct 10 (NOAA Climate Normals 1991-2020). Counting from the latest last frost to the earliest first frost, that's a 101-day window you can count on — up to 162 days on a mild site in a kind year.
Frost tenderness
False Sunflower is frost-tender — its listed minimum temperature is 51.8°F (USDA PLANTS Database) — so set plants out after the last frost has cleared your local site, not the state's earliest date.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
Zone compatibility says you can survive winter here. Whether the growing season is long enough — and warm enough — is a different question.
Frost-free days
False Sunflower wants 90+ frost-free days; a typical New Hampshire site sees ~170 (NOAA Climate Normals). That leaves comfortable headroom for succession planting.
Climate aggregates derive from USDA NRCS county-level hardiness data + Cornell CALS Extension GDD-by-region tables + MSU Extension chill-hours-by-zone (1991-2020 NOAA Climate Normals baseline).
Soil + Drainage Fit
False Sunflower likes near-neutral soil (pH 5-7.5). That's the common-ground band across New Hampshire's glacial till and sandy loam — a soil test confirms it for your site. Drainage matters: this plant wants well (dry spells). If your New Hampshire site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH and drainage requirements from USDA PLANTS Database. New Hampshire soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
False Sunflower in New Hampshire — Quick Answer
- Verdict: Generally — Most Areas
- Plant Zones: 4-9 (USDA PLANTS Database)
- State Zones: 3b-6a (USDA ARS PHZM 2023)
- Growing Season: May 1 - Jun 1 to Sep 10 - Oct 10 (NOAA Climate Normals)
What Else to Consider
Zone compatibility tells you about winter cold survival — but New Hampshire growers also need to think about:
Very short season in the White Mountains (80-100 frost-free days)
In the mountains, fast varieties plus a cold frame or hoop house turn 90 days into a working season.
Rocky glacial soils throughout the state
Build up rather than dig out — a raised bed over cleared ground beats fighting granite for every planting hole.
Harsh winters with deep snow cover
Deep snow is a blanket, not a threat — plant to your true zone and the cover protects what the cold would test.
Pollinator + Wildlife Value
False Sunflower draws pollinators (high value, USDA PLANTS Database). Planting it near vegetable beds can lift fruit set on neighboring crops.
New Hampshire Cooperative Extension
For New Hampshire-specific cultivar recommendations, planting calendars, and pest pressure for false sunflower, the canonical source is UNH Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is False Sunflower native to New Hampshire?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents False Sunflower as native to New Hampshire. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing False Sunflower in New Hampshire
When can I plant False Sunflower in New Hampshire?
New Hampshire's last spring frost clears between May 1 and Jun 1, and the first fall frost lands between Sep 10 and Oct 10 (NOAA Climate Normals 1991-2020). False Sunflower is frost-tender — its listed minimum temperature is 51.8°F (USDA PLANTS Database) — so wait until the last frost has cleared your specific site before planting out.
What hardiness zone is False Sunflower grown in across New Hampshire?
New Hampshire spans USDA hardiness zones 3b-6a (USDA ARS PHZM 2023). False Sunflower carries a range of zones 4-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical New Hampshire site have?
A typical New Hampshire site sees ~170 frost-free days per year (derived from NOAA Climate Normals 1991-2020). False Sunflower needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is False Sunflower native to New Hampshire?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents False Sunflower as native to New Hampshire. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for False Sunflower in New Hampshire?
False Sunflower prefers pH 5-7.5 and well (dry spells) drainage (USDA PLANTS Database). That sits in the common-ground band across New Hampshire soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will False Sunflower actually grow on my specific land in New Hampshire?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores false sunflower against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in New Hampshire
State-level data is a sketch. Your Growable Ground report scores false sunflower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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